Oscar and Reeva had a fight, a horrible argument: Mrs Steenkamp

Johannesburg: Reeva Steenkamp's mother does not believe Oscar Pistorius accidentally killed her daughter and feels "let down" by South Africa's justice system, according to a memoir published yesterday.

Reeva Steenkamp and Oscar Pistorius

In 'Reeva, a mother's story' June Steenkamp said she believes Pistorius shot her 29-year-old daughter dead after a fight and that the couple's relationship had been coming to an end.

"Oscar's story I don't believe," she wrote in the book, released weeks after the athlete was found not guilty of murder and sentenced to five years in prison on a lesser manslaughter charge.

Pistorius claimed that he mistook Steenkamp for an intruder, firing four shots through a locked bathroom door.

"Not one of his actions suggests he felt protective towards her," wrote Steenkamp, the grieving mother setting out what she believes happened in the early hours of Valentine's Day 2013.

June Steenkamp

"They had a fight, a horrible argument, and she fled to the bathroom with her mobile and locked the door.

I think he may have shot once and then he had to go on and kill her because she would have been able to tell the world what really happened, what he is really like. There is no doubt in our minds: she had decided to leave Oscar that night," she wrote.

Steenkamp also described the desperate pain of not being there to help her daughter in her time of need, of medication to numb the anguish and of her husband Barry's recent stroke. "One bullet blew the brains out of her skull," she said.